The field of the invention is medical information devices and more specifically the field of device enhanced IV bags, pumps and pump assemblies that cooperate to reduce the potential for mis-medication and that substantially reduce pump assembly clutter.
While the present invention is applicable to any of several different IV type systems including syringe, bag, cartridge, etc., in order to simplify this explanation prior art and the present invention will be discussed in the context of a bag type IV system. In addition, while any of several different hospital personnel may be able to administer services and medications to a patient within a hospital, to simplify this explanation the term “physician” will be used to indicate any person that renders services or medication within a facility unless indicated otherwise. Moreover, the term “medicant” will be used to refer generally to any type of liquid solution for delivering substance to a patient via an infusion pump. Furthermore, while the present invention may be used in conjunction with infusion systems including a single pump unit, the invention is particularly useful in cases where a system includes several pump units and therefore the invention will be described in that context unless indicated otherwise.
While there are several different ways to deliver drugs, nutrients, etc., to a patient, one of the most widely adopted delivery systems is the infusion pump system wherein drugs or nutrients to be delivered to a patient are dissolved in a liquid solution and stored in a container, typically a bag, that is linked through an infusion pump unit to the patient's blood stream via an intravenous (IV) tube and a needle. Infusion pump systems are advantageous because the amount of substance delivered to the patient over time can be regulated by setting the concentration of the solution and/or setting the pumping rate. To this end, typically an infusion pump unit is equipped with some type of pump controller that can be manually manipulated by a physician to modify substance delivery rate and liquid volume.
Often more than one medicant must be delivered to a patient at any given time. To accommodate simultaneous delivery of a plurality of medicants, most facilities simply provide a separate pump for each of the medicants. For instance, where ten medicants are to be simultaneously delivered to a single patient, ten separate pumps, IV lines and IV bags are provided. In effect, the separate pump unit systems are supplementable to accommodate whatever number of medicants need to be delivered to the patient. To organize several pump units and minimize the space required to accommodate the pump units, often a shelving assembly is provided that organizes the units in a vertical fashion (i.e., one unit above another).
In the past the task of managing medicant infusion processes was relatively simple as most patients were administered only one or a two medicants at any given time. Recently, however, medicant delivery management has been made more difficult due to the large number of different medicants now available. For instance, a patient with five symptoms may now be administered five separate medicants, one medicant to address each of the five separate symptoms. In addition, where five separate medicants are delivered, the medicant volumes may have to be balanced so that a total medicant volume does not exceed a maximum safe volume to be delivered to a particular patient. Also, prior to delivering specific medicants, special protocols have to be performed. For instance, an exemplary protocol may require that a patient's temperature be taken where the medicant can be delivered only if the temperature is within a specific range. As another example, some medicants should only be delivered on an empty stomach and a physician should determine, prior to delivery, the time since the patient's most recent meal.
Moreover, where the total safe volume corresponds to a patient's size (i.e., weight, height, muscle mass, etc.), the total safe volume may change over time so that the volumes of each of the medicants has to be adjusted over time. Furthermore, it may be that a particular patient is allergic to specific medicant “cocktails” (i.e., mixtures) such that medicant mixtures have to be modified over time. Thus, during the course of a patient's stay at a medical facility, it is often that case that the rate of medicant delivery and the medicants delivered must be altered several times as a function of patient conditions.
To facilitate infusion pump setting and real time medicant delivery rate and volume adjustments during a patient's stay at a facility, most infusion pump systems are provided with some type of manual interface device that facilitates simple infusion setting alterations. Because there are only a small number of infusion settings, the interfaces may be relatively minimal including a small display and a small number of input keys (i.e., volume increase and decrease buttons, etc.). Minimal interfaces are relatively inexpensive and therefore expandable systems (i.e., systems that accommodate additional medicants by adding additional pump units) often include a separate interface device attached to each one of the pump units. For instance, if a system includes ten pump units, the system would also include ten separate interface devices for setting infusion parameters.
While expandable systems like those described above have various advantages (e.g., system hardware can be expanded and eliminated as desired), such expandable systems also have several shortcomings. First, clearly, as with any system, as more components are added to the system, the physical components of the infusion pump system become more difficult to track and manage. For instance, distinguishing system lines is important as pump unit settings have to be adjusted as a function of the medicant linked to a particular pump. In this regard, every time another pump unit and corresponding medicant bag are added to a system, an additional IV line has to be added to the system to link the bag and the corresponding pump.
While an additional line may not seem to cause much confusion at first, as several lines are added to the system, the lines begin to resemble spaghetti (i.e., the lines all have a similar appearance) and it becomes difficult to distinguish one line from the others. The task of distinguishing lines is exacerbated as most IV pump systems are simply located in any available suitably sized space within a patient's room and often have to be moved to accommodate other medical equipment. Thus, IV systems are often provided on wheeled upright supports that can be moved about a patient within the patient's room. Such movement can cause a plurality of IV lines to become entangled.
Similarly, because expandable systems typically include a separate interface for each pump unit, the task of employing the interfaces can be tedious. For instance, where there are a large number of interfaces (e.g., 8-10) that are stacked on a unit shelf, the lower interfaces may be difficult to observe. In addition, because pump systems are often moved to accommodate other medical equipment, often the systems have to be manipulated into observable orientations prior to using the interfaces.
Second, in addition to problems associated with the physical components of expandable systems, such systems also can lead to inadvertent mis-medication problems. For instance, as indicated above, where several IV bags are linked to a patient via several pump units and IV lines are crossed one or more times, a physician could easily mistake one pump unit for another and adjust or set an infusion setting for one medicant meant for another.
Third, where several medicants are simultaneously delivered to a single patient even a simple process of modifying medicant delivery rates can be complex. For instance, assume that ten medicants are being delivered to a patient and that a physician wishes to increase one of the medicant delivery rates. In this case, to ensure that the total volume of medicant delivered does not exceed the maximum safe volume, the physician would have to manually examine each of the pump unit interfaces to identify each medicant volume, add up the volumes and then determine if the desired increase is acceptable. In the event that the desired increase would increase the total volume to a level above the maximum, if the physician still wants to facilitate the increase, the physician has to determine which of the other medicant delivery rates can be decreased. Clearly this decision making and adjusting process is arduous. A similar process would be required if an additional medicant were to be added to the medicants being administered to the patient.
Fourth, record keeping in the case of an expandable infusion system can be difficult. To this end, to facilitate billing, historical archiving and diagnostic and prescriptive needs, virtually every modification to medicant delivery should be recorded in detail including the rate change, the medicant for which the rate was changed, the time at which the rate was changed, etc. With conventional infusion systems all changes have to be manually recorded in a patient's bed side chart for later transcription into an electronic filing database. Just as simple modifications to delivery rates are tedious to facilitate, so to are the records that indicate the modifications. For instance, consider again the case where ten medicants are administered to a patient and a physician intends to increase one of the medicant delivery rates. If other medicant delivery rates have to be altered to accommodate the increase in the one medicant, the physician has to make the modifications to other rates and then record each of the modifications.
U.S. Pat. No. 5,980,501 (the “'501 patent”) teaches one infusion system wherein an electronic memory is provided on a medication bag where medication information is stored on the memory and can be obtained from the memory when an information reader is placed adjacent the memory. The reader is linked to the bag adjacent the memory via a clip and is linked to a controlling pump unit via a data cord to provide medication information to the pump for regimen control purposes.
While the concepts in the '501 patent address various problems with prior art including pump programming problems that have lead to mis-medication in the past, the concepts in the '501 patent have several shortcomings. First, by requiring both a cord and an IV tube to be linked between each IV bag and a corresponding pump unit, the number of connections between IV bags and pump units is doubled. While additional connections may not be confusing in cases where only a single bag is linked to a patient, additional connections where more complex configurations are employed increase the likelihood of confusing which bags are linked to which pump units as IV lines and data cords often have similar appearances and may cross each other several times between corresponding bags and pump units.
For instance, assuming that four separate medicant bags are to be linked to a patient A. It is possible that a physician could link a single pump unit to a data cord corresponding to a first medicant and to an IV tube corresponding to a second medicant so that the information obtained from one of the information devices would be used to control administration of some other medicant and vice versa. Clearly such an inadvertent mix-up would cause mis-medication.
As another instance, again assume that four separate medicants are linked to a patient through a pump including seven inlet ports and a single outlet port that links to the patient and that a physician has manually adjusted settings for each of the separate medicants via a pump interface where the manual settings are different than the settings specified in the memory devices. Also assume that three of the four medicants have to be replaced. In this case, the physician has to trace the IV tubes from each of the medicants to be replaced to the corresponding pump units and disconnect the tubes from the corresponding pump unit inlet ports. After retrieving the replacement medicant bags, the physician has to make sure that the replacement bags are linked to the inlet ports from which the corresponding empty bags were removed. This can be accomplished by observing the pump interfaces to determine which units are associated with which medicants and then linking up the tubes to the pump units. These tracing and confirmation tasks are tedious at best and clearly could lead to configuration and medicant delivery errors.
Second, the simple task of determining which of several medicants is almost gone where several medicants are being delivered through a pump assembly to a single patient is also tedious. With the '501 patent system a physician has to either manually place the IV bag that is low on medicant within the physician's line of sight and read the information there from or has to trace the IV tube from the low medicant bag to the corresponding pump unit and obtain the medicant information there from. As known in the industry medicant bags are typically relatively flimsy and are often hung on IV stands such that medicant labels are not always easy to observe. As indicated above, tracing tubes to pumps is difficult.
Third, the '501 patent fails to facilitate record keeping tasks. To this end, while the '501 patent teaches a system for downloading prescription information into a pump unit and also teaches an interface for manually modifying infusion settings, the '501 patent fails to teach any way of tracking and recording manual delivery modifications.
Fourth, the '501 patent system does not overcome the problems discussed above with respect to multiple interfaces (i.e., a separate interface for each pump unit).
Fifth, while the '501 patent teaches that bag memories should be disabled after a single use, the '501 patent fails to recognize that the same information stored in a bag memory may be included in a pump unit memory and could be used to administer other medicants to a patient. For instance, assume that a medicant A bag is empty and is to be removed from a pump unit. After removing the empty bag, the pump unit settings remain set in the pump unit. If another bag were linked to the pump unit, the unit may use the current settings to deliver medicant to the patient.
Sixth, the '501 patent system fails to teach correlation of a medicant with a particular patient or prescription prior to delivery. For instance, when a bag is linked to the '501 patent pump, the pump simply obtains information from the bag and adjusts pump settings as a function of the obtained information. The '501 patent then begins medicant delivery according to the settings without regard for whether or not the patient linked to the pump is the patient for whom the medicant was released from the pharmacy.
Seventh, the '501 patent system can inadvertently carry out a stale medicant regimen either on the patient for which a medicant was dispensed or on another patient. For instance, a bag memory could be retrieved by the '501 patent system and stored in a system memory prior to linking the medicant to a patient A, the patient for whom the medicant was intended. Several minutes later patient A could be moved within the facility and a patient B could be placed in patient A's position. In this case, medicant A may be administered to patient B inadvertently. While the '501 reference teaches including an expiry date on each memory device, such an expiry date would not overcome mis-medication like that described above.
Other prior art references have addressed some of the shortcomings of the '501 reference. For instance, with respect to reducing confusion among several pump units and corresponding IV lines, U.S. Pat. No. 5,713,856 (hereinafter “the '856 patent) teaches a system including a single patient interface unit and a plurality of linked functional units where each functional unit may be a separate infusion pump unit. A system operator uses the interface unit to set parameters for each of the functional units. The functional units are integrally mounted to the interface unit and receive instructions there from regarding infusion rate, volume, etc.
The '856 patent system is advantageous as it requires only one interface and a reduced number of IV lines and data cords. Nevertheless, the '856 system still has some of the shortcomings associated with the '501 patent and also has additional short comings such as requiring either manual entry of medicant information or a correlating process whereby medicant in a bag is correlated with medication/prescription information from a medication or patient record.
Other references teach systems where patient information can be read by bar code readers and the like so that systems can automatically determine if a medication is administrable to a particular patient (i.e., determine if the patient is allergic to a medication, determine patient blood type, etc.). These systems, however, typically operate on a pre-delivery basis (i.e., at a physician's office or at a facility pharmacy) and not as a function of patient conditions or circumstances at the time of medication delivery. For instance a patient may be allergic to a medicant combination including medicants A and B. The patient's allergy may not be noted in the patient's chart and therefore, even where the patient is currently being administered medicant B, a physician may prescribe and administer medicant A thereby causing an allergic reaction. Even where the patient's allergy is noted on the patient's chart, a physician may inadvertently fail to notice the allergy and prescribe medicant A despite current delivery of medicant B. Similarly, even where a physician recognizes the allergy, the physician may inadvertently or accidentally prescribe medicant A despite current delivery of medicant B. Thus, while existing systems can recognize various drug combinations that should be avoided, often those systems are not linked to an IV system and therefore cannot alert physicians of potential mis-medication at the time of delivery.
Thus, there is a need for an IV system that enables simpler interfacing and more specifically a system that facilitates accurate prescription entry, verification that prescriptions are suitable at the time of delivery, avoidance of delivery of stale prescriptions, accurate and automatic delivery record keeping, a simple IV linking and de-linking protocol and simpler interfacing for monitoring and system setting modifications.